The AutoIt IDE removes the WS_CLIPCHILDREN window style when creating the
component. The WS_CLIPCHILDREN window style excludes the area occupied by child windows when drawing occurs within the parent window.
The AutoIt documentation of GUICtrlCreateObj methods says: "'Document
Objects' will only be visible if the Windows style $WS_CLIPCHILDREN has been
used in GUICreate().".

The following script shows how you can add the
WS_CLIPCHILDREN and WS_CLIPCHILDREN
styles to the form and the component itself.